Rotary electrical device

Abstract

A rotary electrical device includes a rotor having a hollow cylindrical shape or a solid cylindrical; and a stator having an annular shape and surrounding a rotation axis of the rotor. The stator includes a winding and a stator core constituted by a magnetic powder core. The stator core includes multiple cores facing each other with the winding interposed therebetween in an axial direction of the stator. One core of the multiple cores includes a yoke contacting another core, and one or more claw magnetic poles that protrude radially from the yoke toward the rotor. The one or more claw magnetic poles are alternately arranged with claw magnetic poles of the one other core. The yoke has a yoke surface parallel to the axial direction, contacting the other core.

The invention claimed is: 
     
       1. A rotary electrical device comprising:
 a rotor having a substantially hollow cylindrical shape or a substantially solid cylindrical shape and configured to be rotatable; and 
 a stator having a substantially annular shape and disposed in a radial direction of the rotor to surround a rotation axis of the rotor, 
 wherein the stator includes a winding that is wound in a substantially annular shape around the rotation axis, and a stator core that surrounds the winding and is constituted by a magnetic powder core, 
 wherein the stator core includes a plurality of cores facing each other with the winding interposed therebetween in an axial direction of the stator, 
 wherein one core of the plurality of cores includes a yoke that is in contact with one other core of the plurality of cores, and one or more claw magnetic poles that protrude from the yoke toward the rotor in the radial direction, 
 wherein the one or more claw magnetic poles of the one core of the plurality of cores are alternately arranged with claw magnetic poles of the one other core, with which or to which the yoke is in contact, in a circumferential direction of the stator, 
 wherein the yoke has at least one yoke surface that is substantially parallel to the axial direction, and 
 wherein the yoke surface of the yoke of the one core of the plurality of cores includes a surface that is in contact with a yoke surface of a yoke of the one other core in the circumferential direction. 
 
     
     
       2. The rotary electrical device according to  claim 1 , wherein a length of the yoke surface in the axial direction is greater than a half of a length of the yoke in the axial direction. 
     
     
       3. The rotary electrical device according to  claim 1 , wherein only the yoke surface of the one core is in contact with the one other core. 
     
     
       4. The rotary electrical device according to  claim 1 , wherein the yoke surface of the one core is in contact with the one other core in the radial direction. 
     
     
       5. The rotary electrical device according to  claim 1 , wherein, in a plan view along the axial direction, the yoke surface is positioned on a line connecting a center of a width, in the circumferential direction, of at least one claw magnetic pole of the plurality of claw magnetic poles to the rotation axis of the rotor. 
     
     
       6. The rotary electrical device according to  claim 1 , wherein the plurality of cores have a same shape. 
     
     
       7. The rotary electrical device according to  claim 1 , wherein the yoke includes a plurality of internal teeth arranged at equal intervals in the circumferential direction, the plurality of internal teeth having a same width in the circumferential direction, and wherein
   θ α =180/(2· n ), and
 
   θ β =360/(2· N ) hold,
 
 
       where θ α  represents an angle in degrees between a center of a width, in the circumferential direction, of each of the claw magnetic poles and an end, in the circumferential direction, of an internal tooth that is closest to the center of the width, n represents a number of the plurality of claw magnetic poles, and θ β  represents an angle in degrees between both ends, in the circumferential direction, of each of the claw magnetic poles, and N represents a number of the plurality of internal teeth. 
     
     
       8. The rotary electrical device according to any  claim 7 , wherein n is equal to N or is a multiple of N.